BANGKOK — Chinese rescuers have freed six people from the rubble of an earthquake in Myanmar, including a child and a pregnant woman, Chinese state media reported Monday, placing Beijing at the forefront of an international rescue effort from which the United States has been largely absent. Rescue teams from India, Malaysia, Russia, Thailand and other countries have already arrived in Myanmar. But a U.S. team has yet to appear at the scene of the quake in the Southeast Asian nation, which occurred the same day the State Department informed thousands of employees of the U.S. Agency for International Development,...